Moulding of plastic containers with handles

Abstract

The production of a container with an integrated handle, by injection moulding a preform with an incorporated handle protrusion, where such protrusion has a direction perpendicular to the axis of the preform and then stretch blow moulding the said preform into a container, where before the end of the blowing step the handle protrusion is deformed into the shape and/or position it will have in the finished container.

1 . A preform for blow moulding a plastics container, wherein said preform comprises a body area, a neck area, and at least one incorporated deformable handle protrusion,
 wherein a first end of the handle protrusion is connected on or adjacent to the neck area of the preform comprising a connection point and a second opposed, free end of the handle protrusion(s) extends outwardly away from the neck such that in an initial position the handle protrusion extends in a direction extending substantially perpendicular to the longitudinal axis of the body area of the preform, and   wherein the second opposed, free end of the handle protrusion(s) comprises a structural feature that enables a secure engagement of the second opposed, free end of the protrusion to the blown body of the container, and   wherein said preform is stretch blow moulded into a container and wherein the handle protrusion(s) is deformable around the connection point into a final predetermined position substantially parallel to or at an acute angle to the longitudinal axis of the body area of the container before the end of the blowing step.   
     
     
         2 . The preform of  claim 1 , wherein said handle protrusion(s) is made from the same material as the preform and produced as an integral member with the preform during injection moulding of the preform. 
     
     
         3 . The preform of  claim 2 , in which the handle protrusion(s) and preform are composed of PET. 
     
     
         4 . The preform of  claim 1 , wherein said handle protrusion(s) is substantially linear in shape, and relatively thin so that it possesses sufficient flexibility in order for it to be deformed from an initial position to a predetermined final position during formation of the container. 
     
     
         5 . The preform of  claim 1 , wherein said handle protrusion(s) is rigid for higher strength, and wherein flexing is possible at the connection point between the handle and the neck area of the preform, said flexing is achieved by the presence of a small thin area, wherein said thin area can flex to act as a pivot around which the handle will be rotated, to take its final position as it will be in the container. 
     
     
         6 . The preform of  claim 1 , in which the structural feature extends at an angle from 90 degrees to 30 degrees relative to the longitudinal axis of the handle. 
     
     
         7 . The preform of  claim 1 , comprising two handle protrusions on opposite sides of their neck area, wherein both of said handle protrusions are deformable so that they can be encapsulated by the blown body of the container so that the container produced will have two handles. 
     
     
         8 . The preform of  claim 1 , wherein the handle comprises a region of increased thickness, at a point between the connection between the handle and the neck area of the preform, and wherein the region of increased thickness retains heat from injection moulding prior to blow moulding such that the region of increased thickness acts as a pivot point around which the handle will be rotated to take its final position as it will be in the container. 
     
     
         9 . A method for producing a container with at least one integrated handle, the method comprising the steps of:
 injection moulding a preform as claimed in  claim 1 ; and   stretch blow moulding of the preform into the container, comprising placing the preform within a blow mould at a predetermined temperature; and stretching and blowing the preform inside the blow mould into a container such that the second opposed, free end of the handle protrusion is encapsulated by the blown body of the container;   
       wherein at any time between preform moulding and the end of stretch blow moulding, the handle protrusion on the preform is bent or deformed from its initial position to a predetermined shape and position to form the finished container. 
     
     
         10 . The method according to  claim 9  wherein preforms are transferred for blow moulding while sufficiently warm such that sufficient heat is retained in an area of increased thickness of the section of the handle protrusion, said area in its warm state being the point of weakness thus enabling the handle protrusion to deform easily at that point. 
     
     
         11 . An apparatus for the production of plastic containers with integrated handles, in which the apparatus comprises:
 injection moulding apparatus for preforms with incorporated handle protrusions as claimed in  claim 1 ;   temperature control apparatus arranged in use to adjust preform temperature and/or to re-heat preforms to stretch-blowing temperature;   apparatus arranged in use to place preforms in the blow moulds.   apparatus for deforming the handle protrusion of the preform into the predetermined shape and orientation of the container; and   apparatus for stretching and blowing the preform inside the blow mould into a container, in a manner that the second opposed, free end of the handle protrusion is encapsulated by the blown body of the container.   
     
     
         12 . A blow mould for enabling the production of bottles from a preform with at least one incorporated handle protrusions as claimed in  claim 1 , wherein said handle protrusion(s) are deformed before the final stages of blow moulding, said mould comprising at least one handle deforming mechanism. 
     
     
         13 . The blow mould of  claim 12  wherein said handle deforming mechanism is partially or wholly incorporated in the blow mould. 
     
     
         14 . The blow mould according to  claim 12  wherein said handle deforming mechanism is partially or wholly independent from the blow mould. 
     
     
         15 . The blow mould of  claim 12  comprising guides that guide the deformed handle from an initial position into its final predetermined position for encapsulation in the blown body of the container. 
     
     
         16 . The blow mould of  claim 15  further comprising a hold mechanism that holds the deformed handle in its final predetermined position, and accurately securing said handle(s) for encapsulation in the blown body of the container.